Firstly, contract law does apply but the contract you are entering is not a contract for the sale of goods. It’s an agreement that you will invest in their company with a view to getting a finished product if there ever is one.
Secondly the pedal design is more expensive to manufacture than the original device, why would it be a bait and switch in that direction? Doesn’t compute.
They ran into an unsurmountable problem, which would’ve been the perfect time to run away with all our money if they had intended to. Instead they put themselves in a hole trying to get a product to market that still meets the needs of a vast majority of their backers.
That alone has convinced me that their hearts are in the right place, they are just terrible at communication and very naive.